1. Field of the Invention
This invention relates to an electrically powered pet door apparatus, more particularly, the invention relates to an electrically powered pet door which any pet can open. The pet door is not opened by environmental factors; the invention does not harm small pets nor their limbs; and, further, this invention relates to a powered pet door which is ready to stand up to abuse without increasing the cost or complexity thereof.
2. Descriotion of the Prior Art
It is common for pet owners or owners of domesticated animals to feel inconvenienced by the dependence of their animals on them. It is inconvenient and undesirable for the pet to be dependent on the owner because the door must be opened when the pet wants to enter or leave the house. Frequently, a pet may need to leave the house early in the morning thereby disturbing and irritating the sleeping pet owner.
In order to remedy the inconvenience these various forms of the call-of-nature bring to pet owners and which are intrinsic in owning a pet, several devices are known which may be opened by animals. Generally, manual pet doors have been available consisting of a door having hinged flappers which close the door after the pet enters or exits through it by means of a spring or elastic rebound means. A typical pet door further consists of a frame mounted around an opening in a wall or entrance door of a house which has the panel or multiple panels attached by the flexible hinge means. The panel itself may be flexible or rigid depending upon the construction desired. A hinge attachment rebound means is generally mounted of the top of the opening in the wall but may be found to be mounted on one or more sides. In the elastic rebound means, the frame may be circular and the panels may be mounted circumferentially therearound forming a shutter type opening. In any case, the panel is arranged such that it tends to be self-closing, that is, by gravity or other elastic properties of the panel causing the panel or panels to close once the pet has passed through.
In addition to the above described forces used for closing, the manual pet doors of the prior art may also employ a seal or are kept in a closed position by use of magnets and/or special configurations on the periphery of the flap thereby keeping it closed. In all cases, in order for the pet to pass through the door, the pet urges or pushes on a panel(s) with its nose or head, thereby overcoming the self-closing action or other mechanical features of the panel. This method of activation presents several disadvantages.
One of the disadvantages of manual pet doors is that their self-closing force must be relatively low so that a pet of small size, weight or strength may overcome the self-closing force and open the door without difficulty. As a direct result, these easily-opened pet doors can also be opened by the forces of nature such as air pressure on a windy day. Thus, these pet doors allow cold air, rain, dirt and other elements to enter the house which further disturbs and irritates the pet owner or spouse. A drafty pet door adds to home heating losses and, frequently, discourages use during the colder winter season. This is a particular problem in the colder regions of the nation wherein the longer colder seasons pre-dominate.
Another disadvantage of a low force self-closing pet door is that it is easily opened by small animals. Other natural forces may also open and allow non-domesticated animals, reptiles or small rodents into the house or living environment of the pet owner. This easy egress becomes a problem in the warmer regions of the nation wherein the warmer seasons are longer and nondomesticated animals do not hibernate. It also concerns and affects pet owners in rural areas and in colder regions during the summer months.
Still another disadvantage of a low force self-closing pet door is that these lack the sturdiness which is necessary to endure the frequent abuses by larger pets and the forces of nature. For example, the repeated abuse of the pet door by a large dog frequently wears it out. Thus, it is desired datum to have a sturdy, more durable pet door.
Another and further disadvantage of an automatic or manual pet door is the periodic maintenance required to ensure functionability of the pet door. In automatic pet doors which have many moving parts, these components may require periodic lubrication or replacement because of the frequent use. The cost of replacement parts adds to the overall cost of the pet door which makes it more expensive over the life of the unit. For manual pet doors, of light weight construction and having a low self-closing force, the components may require replacement or reattachment which increases the inconvenience to the pet owner and overall cost of the unit.
Yet another disadvantage is the pinch hazard problem created by hinged manual pet doors. A pet door which is comprised of hinged flappers which close after the pet enters or exits, by a spring or other elastic rebound means, contains a pinch hazard to pets, especially smaller pets. A pinch point exists between a hinged flapper and the opening created in a wall or entrance door of a house wherein the elastic rebound may cause the flap and wall to jointly strike or "pinch" a paw or other extremity of the animal thereby causing injury. Furthermore, continuous injury to a pet through a pinch point tends to discourage the domesticated pet from using or opening the pet door thereby rendering it useless.